ballistics for the ems provider how guns work, what they can do, and how to treat gun shot wounds...
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Ballistics for the EMS Ballistics for the EMS Provider Provider How guns work, what they How guns work, what they
can do, and how to treat gun shot woundscan do, and how to treat gun shot wounds
Jeff Brosius,
B.S., NREMT-P, CCEMT-P
Basic Principles of BallisticsBasic Principles of Ballistics
PhysicsFirearm mechanicsBullet propertiesTissue response to forceTreatment
Basic Principles of Physics Basic Principles of Physics
Kinetic Energy is a function of mass and velocity
Force is a function of mass and acceleration/deceleration
Energy can not be created or destroyed, only changed from one form to another
Newton’s Laws of EnergyNewton’s Laws of Energy
Kinetic Energy = ½ Mass x Velocity²Force = mass x G (where G = Gravity ForceA body in motion will continue in motion
until acted upon by an outside force (tissue, gravity, friction, solid object, etc.)
Firearm MechanicsFirearm Mechanics
All firearms share some basic principles.There is a barrel, which functions to direct
the projectile in a certain direction.There is a pin, which causes the powder in
the bullet to ignite.There is a trigger, which causes the pin to
strike the bullet.
Firearm Mechanics, cont.Firearm Mechanics, cont.
The bullet contains powder, which will burn rapidly, creating gas vapors.
These vapors expand inside the barrel, creating pressure.
The pressure forces the bullet out of the barrel.
The speed of the bullet depends on several factors (size, friction, etc.)
Bullet CharacteristicsBullet Characteristics
Caliber of the bullet (.22, .45, .357, 9mm, etc.)
Blunt vs. Hollow vs. Pointed endCasing (unjacketed/full metal jacket)Density of material
Handguns, by the NumbersHandguns, by the Numbers
Caliber Velocity Muzzle Energy Energy at 45 feet
Ft/sec
.25 810 73 60
.32 745 140 120
.357 1410 540 475
.38 855 255 255
.40 985 390 365
.44 1470 1150 875
.45 850 370 350
9 mm 935 345 315
Rifles, by the NumbersRifles, by the Numbers
Caliber Velocity Muzzle Energy Energy at 300 ft
.22 Hornet 3770 1735 1262
.243 3500 1725 1285
M-16 3650 1185 805
Uzi 1500 440 277 (150 ft)
AK-47 3770 1735 1262
Tissue ResponseTissue Response
Cavities – temporary and permanent– Temporary is larger than the size of the bullet,
and is caused by compression of air around the projectile.
– Permanent is the destroyed tissue from the bullet itself.
CavitiesCavities
The size of the cavity is not simply a factor of the bullet size. Other factors are important, but often unknown– Deflection– Yaw of bullet at impact– Speed of bullet at impact– Angle of impact– Range from gun to target
Tissue ResponseTissue Response
Dense tissue will suffer more damage than hollow tissue. (Bone vs. lung)
Elastic tissue will suffer less damage than rigid tissue. (Muscle vs. liver)
Strong tissue will withstand damage better.
Treatment GoalsTreatment Goals
Safety!!!!!!!!!!!!!!!!!!ANY penetrating trauma should be treated
with the utmost urgency.A small hole on the outside might be hiding
a large hole inside.A large hole outside can mask massive
internal damage.
Treatment GoalsTreatment Goals
ABCs, as always.Rapid scene times… grab ‘em and get
moving to the hospital.Airway support to include intubation (more
often needed for thorax injuries.)Ventilatory support as needed.IV enroute, fluids as protocol/Med Control
requests.
Treatment GoalsTreatment Goals
Hemorrhage control if possible.Occlusive dressings for sucking chest
wounds.Needle Thoracostomy as needed for tension
pneumothorax.Bilateral needle decompression ONLY in
an intubated patient.
Treatment GoalsTreatment Goals
Early notification of the hospital.Constant reassessment…A GSW to the
chest can cause the patient’s condition to change RAPIDLY. Be vigilant.
Again, rapid transport is the single best method for treating a gunshot victim.
Nothing else will be as helpful as a physician and hospital trauma care.
Treatment PitfallsTreatment Pitfalls
Wasting time looking for the bullet or shell casing. Thinking that a small hole is not a major issue. Wasting time trying to classify wounds as
entrance or exit. Closest facility vs. Closest appropriate facility. Delaying transport for ANY reason, other than
EMS crew safety.
Controversial IssuesControversial Issues
Cervical Spine Immobilization.Large volumes of fluid replacement.Traumatic cardiac arrest treatment.
AcknowledgementsAcknowledgements
Andres M. Rubiano, MD David H Livingston, MD, FACS Manuel Sotelo, MD Errington C. Thompson, MD Eric D. Ladenheim, MD M.L. Fakler, MD Grady Memorial Hospital, Atlanta, GA Emory University School of Medicine,
Department of Surgery
Web SitesWeb Sites
ww.umds.ac.uk http://medstat.med.utah.eduhttp://igm.nlm.nih.gov/http://www.vnh.org/EWSurg/EWSTOC.htmlhttp://internet.cybermesa.com/~jbm/ballistics
/calculations.htmlhttp://www.firearmstactical.com
Web SitesWeb Sites
http://www.iwba.com/http://www.milnet.com/milnet/weapons.htmhttp://www.wwa.com/~dvelleux/htmlhttp://www.vnh.org/EWSurg/EWSTOC.html
Final Words….Final Words….
Don’t waste time. What you can’t see will kill the patient.
Be safe. Treat the patient. Do not treat the bullet, and don’t waste time on
details that don’t matter. Understand that a .22 is just as lethal as a .357. Don’t waste time.